JPH08328320A - Image forming device - Google Patents

Abstract

PURPOSE: To increase a double-sided printing speed in accordance with a changed memory capacity, at the time of extending memory, in the case double- sided printing is attained in such a manner that data wanting printing on both sides is stored in memory by the paper sheets of the double of a specified number pages, first, the data of even numbered pages is printed on the front surface of the paper sheets for instance and the paper sheets are turned upside down, to be housed in a double-sided printing tray part and fed to a printer in a state where the paper sheets of the specified number are aligned, to print the data of odd numbered pages at this time, in a double-sided printer. CONSTITUTION: The paper sheets are turned upside down in accordance with the capacity of the extended memory 202A, to change the specified number of the paper sheets housed in the double-sided unit 205. For instance, for 8M-byte memory 202A, three sheets are housed, for 12M-byte memory 202A, six sheets are housed and for 16M-byte, nine sheets are housed. As the number of the housed sheets is larger, a mechanical operation time required for switching the feeding direction of the sheet is made shorter. Thus, the double-sided printing speed can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a function of performing double-sided printing, and a double-sided unit according to the capacity of storage means (onboard memory) capable of storing data to be printed. The present invention relates to an apparatus that enables high-speed double-sided printing according to the capacity of a storage unit by changing the number of sheets stored at one time.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional image forming apparatus for performing double-sided printing. In FIG. 7, 101 is a paper feed unit for feeding the output paper 100, and two trays 101A and 101B.
Have. An output unit 102 prints the expanded data on an output sheet. Reference numeral 103 denotes a reversing unit that reverses the front and back of the output paper, and 104 denotes a double-sided tray portion that temporarily stores the reversed output paper. Both 103 and 104 form a double-sided unit. Reference numeral 105 denotes a paper discharge unit that discharges output paper. In the case of performing double-sided printing by the image processing apparatus having such a configuration, conventionally, (1) after printing the front surface of one sheet of output paper, the reversing unit section 103 reverses the output paper sheet and subsequently prints the back surface.

(2) Data of a predetermined number of pages × 2 pages is stored in the memory, and the output unit 102 continuously prints only the front surface (for example, data of even pages) for the predetermined number of pages. Double-sided tray section 104
After that, the data is sent again to the output unit 102, and only the back surface (for example, data for odd pages) is continuously printed this time.

The following method was used.

[0005]

However, if the front surface and the back surface are printed one by one as in (1), not only the conveying system becomes long, but also double-sided printing takes too much time. In addition, as in (2), the method is to print the front side for the specified number of sheets first, and then print the back side continuously.
It takes less time than the method (1). However, even if the user wants to perform double-sided printing at higher speed and increases the memory, the time for double-sided printing has not changed.

That is, even if the memory is expanded,
Unless the predetermined number of output sheets to be put in the double-sided tray unit 104 at the same time, the mechanical operation time required for switching the output sheet feeding direction does not change.
Since the time of this mechanical operation accounts for a large proportion of the entire double-sided printing time, the double-sided printing time is long.

The present invention has been made to solve the above problems, and requires less time for double-sided printing than the method (1). In the method (2), double-sided printing is performed depending on the increase in memory. An object of the present invention is to provide an image forming apparatus capable of high speed.

[0008]

The present invention has been made in order to achieve the above-mentioned object, and comprises a storage means capable of storing data to be printed, and an expansion means capable of expanding the storage means. Output means for outputting even-numbered pages or odd-numbered pages of the data stored in the storage means to output paper for double-sided printing, and reversing the front and back of the output paper on which the data has been output A double-sided unit for temporarily storing the number of sheets and then sending it to the output unit, and a unit for changing the predetermined number of output sheets to be stored in the double-sided unit according to the capacity of the storage unit are provided.

[0009]

When the user expands the storage means by the expansion means, the predetermined number of output sheets stored in the duplex unit is changed according to the change in the capacity of the storage means. Then, of the data stored in the storage means, first, data for even pages or odd pages is output to the back or front of the predetermined number of output sheets. Then, after each output sheet is reversed and temporarily stored, it is sent out again to the output means in a state where the changed predetermined number of sheets are aligned, and this time, data for odd pages or even pages is output to the back or front. To be done. In this way, double-sided printing according to the capacity of the storage means becomes possible.

[0010]

FIG. 1 is a block diagram showing the configuration of an image forming apparatus showing an embodiment of the present invention.

In FIG. 1, reference numeral 201 denotes a reader unit for converting a document into image data, and also serves as an image input device for inputting image data sent from an external device. A printer unit (output unit) 202 has a tray (not shown) capable of sending out a plurality of types of output paper, and outputs image data as a visible image on the output paper according to a print command. The printer unit 202 is a memory (storage unit) capable of storing data to be printed.
202A can be expanded by the expansion means 202B. Reference numeral 203 denotes a sorter for sorting output sheets sent from the printer unit 202, 204 an operation unit for making various settings and displaying the current state, and 205 a double-sided unit for reversing the output sheets and temporarily storing them during double-sided printing. These 201, 102, 203, 204 and 205 form a digital copying machine A and are connected to an external device B by an external interface (not shown).

The external device B includes a FAX unit 206, a FAX
Storage unit 206A connected to the computer, computer interface unit 20 for connecting to a computer
7, a formatter unit 208 for converting information from a computer into a visible image, a core unit 209 for controlling the functions of the respective units, a computer 210 connected via a computer interface unit 207, and the like.

Computer interface unit 207
Interface with the computer 210 connected to the external device B. The computer interface unit 207 includes a plurality of interfaces for communicating with SCSI, RS232C, and Centronics, and data and commands sent via these three types of interfaces are passed to the core unit 209. The core unit 209 determines whether this data is data related to the FAX unit 206 or data related to the formatter unit 208. In this way, the data and commands from the outside are distributed by the core unit 209 to the portions 206, 207, and 208 having the designated function. In this way, each FAX of the external device B is transferred from the computer 210.
The functions of the unit 206, the formatter unit 208 and the like can be freely controlled.

The present invention will be described in detail with reference to FIGS. 2 to 6. Each of these figures shows the main part of FIG. The present invention does not perform front and back printing for each output sheet, but performs double-sided printing (called skip double-sided) at high speed by storing a predetermined number of output sheets with one side printed in the duplex unit 205. is there.

First, both sides of the skip will be described with reference to FIG. The reader unit 201 and the core unit 209 are omitted between the printer unit 202 and the formatter unit 208. The formatter unit 208 receives the format data from the computer 210 via the computer interface unit 207. Here, when the received data has the amount of 6 pages, the formatter unit 208
First, in order to print the back side, the data of the second page is expanded into bitmap data, and the printer unit 2 is transferred via the bus.
02, prints on output paper, and prints on the duplex unit 205.
Invert to and store temporarily. Similarly, the data of pages 4 and 6 are repeated in this order. The three output sheets thus printed on one side are stored in the duplex unit 205 (see FIG. 2).
(A)).

Next, in order to print the data of the fifth page on the front side, the output paper on which the sixth page has been printed is taken out from the duplex unit 205 and sent to the printer section 202 for printing. The printed output paper is output to one paper tray of the sorter 203 (FIG. 2B). Similarly, the data of the third page is printed on the front surface of the output paper on which the fourth page is printed on the back surface (FIG. 2C), and the data of the first page is printed on the back surface of the second page. Print on the surface of the paper (Fig. 2
(D)), a series of skip both sides is completed.

FIG. 3 shows a procedure for double-sided printing (skipping double-sided) of 12 pages of data with a memory (storage unit) having the same capacity as that of FIG.

That is, it is a sequence diagram of both sides of the skip in the case of the printer unit 202 having the memory 202A of 8 Mbytes. With 8 Mbytes, the intermediate code body (the code transferred from the computer is converted into a format that can be read by the printer) can hold up to 6 pages at the maximum, so the duplex unit 205 can output only up to 3 sheets of output paper. I can't save. In other words, as described above, the page order of the data sent from the computer 210 must be changed in order to perform both sides of the skip. Therefore, at the time of 8 Mbytes, the data for 6 pages, which is the maximum even page, is required. Need to hold.
Therefore, when processing the data for 12 pages, double-sided printing is performed twice as shown in FIG.

First, the data of the eighth page, the data of the tenth page, the data of the twelfth page are printed on output paper, respectively, and the output paper is reversed and temporarily stored in the duplex unit 205 (FIG. 3B). Then, the output paper is taken out from the double-sided unit 205 in order from the top, and the data on the 11th page, the data on the 9th page, and the data on the 7th page are printed on the back side in this order (FIG. 3C). With this, double-sided printing for one time is performed.

Next, printing is performed on one side in the order of the second page, the fourth page, and the sixth page, which is reversed and temporarily stored (FIG. 3 (d)). Then, the stored output sheets are taken out in order from the top, and the data on the fifth page, the data on the third page, and the data on the first page are printed on the opposite side in this order. As a result, the second double-sided printing is performed. Then, 12 pages of data are printed on both sides of 6 sheets of output paper.

However, when a 4-Mbyte SIMM (memory to be added (memory unit)) is added to the expansion slot (expansion unit 202B (see FIG. 1)) of the memory, the memory becomes 12M bytes, which is smaller than that of 8M bytes. It becomes possible to hold intermediate code bodies of many pages (12 pages). Therefore, as shown in FIG. 4, the predetermined number of output sheets stored in the duplex unit 205 can be changed to a maximum of six sheets. This predetermined number of sheets may be changed manually or automatically by a manual device.

With this change, it is possible to perform double-sided printing while accumulating a maximum of 6 output sheets.
That is, data for 12 pages to be printed (see FIG.
In (a)), first, the data of the second page, the data of the fourth page, the data of the sixth page, the data of the eighth page, the data of the tenth page, and the data of the twelfth page are respectively printed on each output sheet. Printing is performed on one side, the output paper is reversed and temporarily stored in the duplex unit 205 (FIG. 4B). After that, the output sheets that have been stored are taken out in order from the top, and the data of the 11th page, the data of the 9th page, the data of the 7th page, the data of the 5th page, the data of the 3rd page, the data of the 1st page Print on the opposite side (Fig. 4-
c). In this way, by adding a 4-Mbyte SIMM to the printer, the memory requirement becomes 12M.
It is possible to perform double-sided printing faster than when using M bytes.

That is, in the time required for double-sided printing, the output paper is mainly printed by the printer unit 202 and the double-sided unit 205.
It's time to interact with. A large proportion of this time is the time required for the mechanical operation required to switch the feeding direction of the output paper. As described above, if the number of output sheets that can be stored in the duplex unit 205 increases, the time required for the mechanical operation for switching can be shortened, and the time required for double-sided printing can be shortened. It enables high-speed double-sided printing.

In the above example, only the case of 8 Mbytes and 12 Mbytes has been described. However, when SIMM, which is a memory having a larger capacity, is mounted, the number of pages to be inserted in the duplex unit 205 at one time is increased, Of course, it is possible to further increase the printing speed.

Next, the control processing of this embodiment will be described with reference to the flowcharts of FIGS. This control processing is executed by control means (not shown) provided in the digital copying machine.

First, when there is an operation input for a copying operation from the operation unit 204, the data to be printed sent from the computer 210 is stored in the memory 202A (step S).
1). Next, it is determined what the capacity of the memory 202A is (step S2), and the maximum number N is set to 8M.
3 for byte, 6 for 12 Mbyte,
When 16 Mbytes, they are set to 9 (steps S3, S4, S5). Then, it is determined whether or not the number of sheets of the data to be printed is larger than the set maximum number N (step S6), and when the former is equal to or smaller than the latter, the sheet number n is set to 0 (step S6). S
7) The data from the second page to the even page is printed on one side of the printing paper, the output paper is reversed and temporarily stored in the duplex unit 205 (step S8). Then, the number n is set to 1
It is incremented (step S9), and it is determined whether or not the number n of sheets has reached the number of sheets of data to be printed (step S10). If not, the next even page, that is, the fourth page, the sixth page, ... Is sequentially printed on one side of each output sheet (steps S8 and S9), and when the number n of sheets reaches the number of data to be printed. , The number of data to be printed × the number of pages 2-1 to odd-numbered pages is printed on the back surface of the printing paper (step S11). For example, when the maximum number of sheets N is set to 6 in step S3 and the number of sheets of data to be printed is 6, odd-numbered pages are printed from 6 × 2-1 = 11th page. And the number of sheets is 1
Decrement (step S12), and the number n is 0.
Is determined (step S13), and if not 0, the next odd page, that is, the ninth page, the seventh page, ... Is sequentially printed on the back surface of each output sheet (steps S11 and S12). ), When the sheet number n becomes 0, the maximum sheet number N is reset to 0 (step S14), and the process ends.

On the other hand, when the number of sheets of data to be printed is larger than the maximum number N in step S6, the sheet number n is set to the maximum number N (step S15), and the data of even pages from the (N + 1) × 2nd page is set. Printing is performed on one side of the printing paper, the output paper is reversed, and temporarily stored in the duplex unit 205 (step S16). For example, when the maximum number N is set to 6 and the number of data to be printed is 9,
The number n of sheets is set to 6 (step S15) and
Data of even pages from (6 + 1) × 2 = 14th page is printed on one side of the output paper (step S16). Then, the number n is incremented by 1 (step S1
7) It is determined whether or not the number n of sheets has reached the number (9) of data to be printed (step S18). If not, the next even page, that is, the 16th and 18th pages, is sequentially accessed. Print on one side of each output sheet (step S1
6, S17), and when the number of sheets n reaches the number of sheets of data to be printed (9), the number of sheets of data to be printed × 2-
The data from the first page to the odd pages is printed on the back surface of the printing paper (step S19). In the above example, 9 × 2-1
= Printing starts from the 17th page. Then, the sheet number is decremented by 1 (step S20), and it is determined whether or not the sheet number n reaches the maximum sheet number N (step S21). If the sheet number n does not reach the maximum sheet number N, the next odd page, that is, 1
The fifth and thirteenth pages are sequentially printed on the back surface of each output sheet (steps S19 and S20), and when the number n of sheets becomes N, the number of sheets of data to be printed-N (=
3) is set (step S22), the data of the second page to the even page is printed on one side of the output sheet, and the sheet is reversed and stored (step S23). Then, the number n is incremented by 1 (step S2
4) It is determined whether or not the number n has reached the number (9) of data to be printed (step S25). If not, the next even page, that is, the fourth page, the sixth page, ... And sequentially print on one side of each output sheet (step S2
3, S24), when the number n of sheets reaches the number (9) of the data to be printed, the number n of sheets is changed to the maximum number N (=
6) (step S26) and the above-mentioned step S
11 and subsequent steps are executed to print an odd page from the 11th page. Even when the maximum number N is set to 3 or 9 in accordance with the memory capacity in steps S4 and S5, the same processing as described above is performed.

As described above, according to the present invention, the more the memory is mounted on the printer, the faster the double-sided printing can be performed. Therefore, the printing speed according to the budget of the user can be provided.

[0029]

As described above, according to the present invention, the predetermined number of output sheets reversed and stored by the double-sided unit can be changed according to the capacity of the storage means added by the user, and the capacity of the storage means. Thus, the maximum number of sheets that can be stored is stored, and therefore the time required for the mechanical operation required to switch the feeding direction of the output paper can be reduced, and high-speed double-sided printing can be performed.

[Brief description of drawings]

FIG. 1 is a diagram of an image forming system according to an embodiment of the present invention.

FIG. 2 is a skip high-speed double-sided sequence diagram.

FIG. 3 is a high-speed double-sided sequence diagram for 8 Mbytes.

FIG. 4 is a high-speed double-sided sequence diagram for 12 Mbytes.

FIG. 5 is a flowchart showing a control process of an embodiment of the present invention.

FIG. 6 is a continuation of the flowchart in FIG. 5;

FIG. 7 is a structural diagram of a conventional image processing apparatus.

[Explanation of symbols]

 101 Paper Feeding Section 102 Output Section 103 Reversing Unit Section 104 Double-Sided Tray Section 105 Paper Discharging Section 201 Reader Section 202 Printer Section (Output Means) 202A Memory (Storage Means) 202B Expansion Means 203 Sorter 204 Operation Section 205 Double-sided Unit 206 FAX Section 206A External storage device 207 Computer interface unit 208 Formatter unit 209 Core unit 210 Computer

Claims (1)

[Claims] 1. Storage means capable of storing data to be printed, expansion means capable of expanding the storage means, and even-numbered pages or odd-numbered pages of data stored in the storage means for double-sided printing. The output means for outputting the minutes to the output paper, the double-sided unit for reversing the front and back of the output paper on which the data has been output and temporarily storing a predetermined number of the output paper, and then sending the output paper again to the output means, and the capacity of the storage means. And a means for changing the predetermined number of output sheets to be stored in the double-sided unit according to the above.